The present invention relates to a motor drive controller for a vehicle and, more particular, to a motor drive controller for a vehicle providing a simplified system to further facilitate a combination of engine control and motor control.
Some vehicles are of a type commonly called a hybrid vehicle having an internal combustion engine and an electric motor disposed therein as a propulsion system. The hybrid vehicle further includes an engine controller for controlling a running state of the engine and motor control means for controlling an operating state of the motor. The engine control means and the motor control means detect respective operating states of the engine and the motor when the vehicle is traveling, and then data on such detected running states are exchanged between the engine controller and the motor controller. As a result, the respective operating states of the engine and the motor are controlled in association with one another. Such a control system attains a high level of required performance (such as a fuel efficiency, a value of detrimental components in exhaust gases, and power performance).
One such example of a vehicle controller is disclosed in published Japanese Patent Application Laid-Open No. 9-238403. A hybrid vehicle as disclosed in this publication has an engine formed by an internal combustion engine, and further has a generator provided on the engine. When the vehicle is dampened, then operating energy of the vehicle drives the generator, thereby generating power. When the vehicle is normally traveling, then excess torque of the engine drives the generator, thereby generating power. Such generated output is stored in order to drive the generator as a motor when the vehicle is accelerated, thereby assisting the engine. The above hybrid vehicle is characterized by control means for controlling driving torque that drives the generator when the vehicle is normally traveling. Such a feature overcomes a torque deficiency that results from power generation associated with the normal traveling of the vehicle.
In a so-called hybrid vehicle controller heretofore employed, the engine control means and the motor control means detect respective operating states of the engine and the motor when a vehicle is running, and then data on such operating states are exchanged between the engine control means and the motor control means. As a result, the respective operating states of the engine and the motor are controlled in cooperation with one another.
At this time, the motor control means calculates required torque according to a detected throttle opening degree, etc., and then produces a torque instruction value for the motor after a decision is made as to how the engine shares work with the motor.
However, such a vehicle controller has the drawback of suffering from a complicated control system because the engine control means and the motor control means execute respective control in conjunction with one another.
Such a complicated control system in the controller brings about other drawbacks including reduced reliability and increased costs.
In order to overcome the above drawbacks, the present invention provides a motor drive controller for a vehicle having an engine and a motor disposed therein as the vehicle propulsion system, the motor having both a drive function and A power-generating function, comprising: an engine controller for controlling a running state of the engine; motor controller for controlling both driving and power-generating states of the motor in a manner independent of control over the engine taken by the engine control means; an engine speed detector for detecting revolution of the engine; and an engine load detector for detecting an engine load, wherein the motor controller includes a map defined by respective detection signals from the engine speed detector and the engine load detector, and wherein the motor controller provides alternative control between driving and power generation of the motor in response to a torque instruction value that is retrieved from the map.
According to the present invention as previously described, the motor controller includes the map defined by the respective detection signals from the engine speed detector and the engine load detector. In addition, the motor controller provides alternative control over between driving and power generation of the motor in response to the torque instruction value retrieved from the map. Such a construction provides a simplified system at reduced costs, and further facilitates a combination of the engine controller and the motor controller.